It's a Chamaeleo gracilis. If you would have typed in 'graceful chameleon' in google you would have know for sure from the start.
It wasn't a guess. Looking for it on the internet gives you plenty of results, senegalensis looks a lot alike but shows different colors. As my internet connection (mobile) is blurring pictures I can't give a detailed explanation about the difference but I might be able to do so later.